Identifying traffic differentiation on cellular data networks

Abstract

The goal of this research is to detect traffic differentiation in cellular data networks. We define traffic differentiation as any attempt to change the performance of network traffic traversing an ISP's boundaries. ISPs may implement differentiation policies for a number of reasons, including load balancing, bandwidth management, or business reasons. Specifically, we focus on detecting whether certain types of network traffic receive better (or worse) performance. As an example, a wireless provider might limit the performance of third-party VoIP or video calling services (or any other competing services) by introducing delays or reducing transfer rates to encourage users to use services provided by the provider. Likewise, a provider may allocate more bandwidth to preferred applications. Previous work [1, 3, 5] explored this problem in limited environments. Glasnost focused on BitTorrent in the desk- Top/laptop environment, and used port/payload randomization to avoid differentiation. NetDiff covered a wide range of passively gathered traffic from a large ISP but likewise did not support targeted, controlled experiments. We address these limitations with Mobile Replay.